1. Field of the Invention
This invention relates to a system of interconnected sludge protector canopy perforated baffles for use in solids separation and settling tanks, the baffle system consisting of a plurality of interconnected perforated baffles attached to other components of the tank and forming a rigid ceiling of sloped and curved perforated baffles covering the sludge layer at the bottom of the tank.
2. Description of the Related Art
The present invention relates to a baffle system for a tank for separation of solids from the water by gravitational forces in water and wastewater treatment. The tank where the inventive baffle device is used is typically circular, square or rectangular in shape.
In water and wastewater treatment where sedimentation tanks, also known in the art as clarifiers or settling tanks, are used, the efficiency of the tanks is governed by the amount suspended matter removed and the quality of the sludge produced from the bottom of the tank. The energy and momentum of the flow entering the tank as well the density currents resulting from the difference in specific gravity between suspended matter and water or the differential temperature between the atmosphere and the water contained in the tank represent a major deterrent to the tank removal efficiency and quality of the sludge produced. High level of energy of the flow entering the tanks and/or strong density currents create strong water fall that disturbs the sludge blanket leading to sludge re-suspension and deterioration of tank performance.
Representative examples of prior art of baffles and the like are disclosed in U.S. Pat. No. 2,702,124 to Stengel, U.S. Pat. No. 3,175,692 to Edgerton, U.S. Pat. No. 3,486,628 to Darby, U.S. Pat. No. 3,966,617 to Zaenkert, U.S. Pat. No. 4,270,676 to Green, U.S. Pat. No. 4,985,148 to Monteith, U.S. Pat. No. 5,378,378 to Meurer, U.S. Pat. No. 5,384,049 to Murphy, U.S. Pat. No. 5,714,068 to Brown, U.S. Pat. No. 6,099,743 to Pederson, U.S. Pat. No. 6,276,536 to Esler and U.S. Pat. No. 6,800,209 to Wright. All these inlet designs focused on dissipating the energy of the incoming water to improve settleablity of the sludge without providing protection to the settled and thickened sludge or prevention of sludge re-suspension.
Other representative examples of prior art are disclosed in U.S. Pat. No. 7,637,379 to Pophali et al., U.S. Pat. No. 7,981,299 to Triglavcanin, U.S. Pat. No. 8,021,559 to Triglavcanin, U.S. Pat. No. 8,087,518 to Kwon et al., and U.S. Pat. No. 8,182,701 to Lake. Some of these inventions presented apparatus for improving thickening of sludge or complete clarifier feed structures comprised of a series of energy dissipating, flocculation and short circuiting baffles. None of the above mentioned inventions was intended to protect sludge blanket only neither could be applied to all tank shapes, circular, rectangular or square.
Moreover, no prior art reference discloses a plurality of interconnected individual perforated baffles sloped in all directions with each baffle containing gas release and water flow-through openings and curved in lateral direction to allow drainage of solids and supported on one or both ends to a structural element within circular, rectangular or square tank.
It is, therefore, an object of the present invention to provide a system of plural, interconnected perforated baffles, supported from the circular feed well, center column and/or energy dissipating tub in case of circular tank or alternatively, attached to the tank inlet wall in case of non-circular tank, forming a rigid ceiling of curved baffle system covering the sludge blanket.